1. Field of the Invention
This invention relates in general to agricultural equipment and in particular to a combine for harvesting and threshing grain using an axial flow threshing and separating means.
2. Description of the Prior Art
U.S. Pat. No. 4,535,787, Aug. 20, 1985, and U.S. Pat. No. 4,489,733, Dec. 25, 1984, show an axial flow combine. The combine has a feeder head with impellers. The feeder head connects to a conical threshing drum. The threshing drum locates forward of a beater. A feeder housing surrounds the feeder head. The feeder housing connects to a threshing housing, which includes a conical grate and a beater housing.
The impellers force the crop into the clearance between the threshing drum and grate, where most of the threshing will occur. A helical flight forces the crop from the threshing drum between the beater and the beater housing. Final separation of grain from crop will occur in the beater housing. The grain will pass through apertures in the beater housing and in the grate into a sieve. The sieve separates and discharges chaff, passing the clean grain into conveying means to transport it to a grain bin.
While this design is workable, it would be desirable to provide more threshing at an earlier stage in the threshing process. This would allow the length of the threshing drum and beater assembly to be shortened.
In the '787 patent the grate and beater housing rotate, but at a much lower speed than the threshing drum and beater. A possibility exists that the crop may become too packed between the threshing drum and the grate or between the beater and beater housing. If this occurred, a possibility exists that the grate and beater housing would start to rotate in unison with the threshing drum and beater. The bearings and supports are not adequate to handle such high speed rotation of the grate and beater housing.